| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1488108 | Materials Research Bulletin | 2015 | 8 Pages |
•Doping with multiple ions (Nb, N, S) enhances the photocatalytic activity of TiO2.•In the multi-doped TiO2, S substituted for Ti whereas N substituted for O.•Multiple doping in TiO2 improves visible light absorption.•Lifetime of the photogenerated charge carriers is higher in multidoped TiO2.•Super oxide, hydroxyl radicals and holes are the active species for dye degradation.
A novel visible light active photocatalyst is synthesized by doping TiO2 with multiple dopants like Nb, N and S. TiO2 exists as anatase phase and the particle size is in the range of 10–25 nm. A significant red shift of the absorption edge and increased visible light absorption is shown by multidoped TiO2 compared to undoped TiO2. The tri-doped TiO2 has the highest activity for the photodegradation of methyl orange and the activity shows the order: 0.6NbNS–TiO2 > P25 > 0.6Nb–TiO2 > NS–TiO2 > pristine TiO2. The enhanced photocatalytic activity of tri-doped TiO2 is due to the reduction of band gap and enhancement of lifetime of photogenerated charge carriers. This multidoped catalyst is found to be stable and only a marginal decrease in the activity is observed upto 3 cycles. Experiments with quenchers suggest that all super oxide, hydroxyl radicals and photogenerated holes are active species for the oxidation reaction.
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